These unusual snails are pelagic, shell-less carnivores, equipped with swimming parapoda, strong jaws and grasping tentacles, often with suckers resembling those of cephalopods.
- bilateral symmetry
having body symmetry such that the animal can be divided in one plane into two mirror-image halves. Animals with bilateral symmetry have dorsal and ventral sides, as well as anterior and posterior ends. Synapomorphy of the Bilateria.
animals which must use heat acquired from the environment and behavioral adaptations to regulate body temperature